The present invention relates to a new and distinct cultivar of Acer ginnala, and will be referred to hereafter by its cultivar name, ‘JefUM’. ‘JefUM’ is a deciduous tree grown for use as a landscape plant.
The Inventors selected the new cultivar, ‘JefUM’, as a seedling in Winnipeg, Manitoba, Canada in the summer of 2000. The seedbed had been planted with seeds collected from an unnamed and unpatented open pollinated plant of Acer ginnala. 
Asexual reproduction of the new cultivar was first accomplished by softwood stem cuttings by the Inventor in Winnipeg, Canada in the summer of 2002. Asexual propagation of ‘JefUM’ by softwood stem cuttings has shown that the unique features of the new cultivar are stable and are reproduced true to type in successive generations.